Form 8-K

8-K — Actinium Pharmaceuticals, Inc.

Accession: 0001213900-26-090232

Filed: 2026-08-14

Period: 2026-08-12

CIK: 0001388320

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

Item: Regulation FD Disclosure

Item: Financial Statements and Exhibits

Documents

8-K — ea0301890-8k_actinium.htm (Primary)

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8-K — CURRENT REPORT

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):

August 12, 2026

ACTINIUM PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its

charter)

Delaware

001-36374

74-2659386

(State or other jurisdiction

of incorporation)

(Commission File Number)

(I.R.S. Employer

Identification No.)

100 Park Ave., 23rd Floor,

New York, New York 10017

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including

area code: (646) 677-3870

Not Applicable

(Former name or former address, if changed since

last report)

Check the appropriate box below if the Form 8-K

filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, par value $0.001 per share

ATNM

NYSE American LLC

Indicate by check mark whether the registrant

is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the

Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check

mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting

standards provided pursuant to Section 13(a) of the Exchange Act. ☐

INTRODUCTORY NOTE

This Current Report on Form 8-K reports the acceptance by NYSE Regulation of the previously disclosed compliance

plan submitted by Actinium Pharmaceuticals, Inc. (the “Company”) on June 18, 2026, and the granting of a plan period through

November 27, 2027 - the maximum period available under Section 1009 of the NYSE American Company Guide (the “Company Guide”)

- during which the Company’s common stock will continue to be listed and traded on NYSE American LLC (“NYSE American”)

under the symbol “ATNM.” This report also furnishes the Company’s related press release.

Item 3.01. Notice of Delisting or Failure to Satisfy a Continued

Listing Rule or Standard; Transfer of Listing.

As previously disclosed, on May 27, 2026, Actinium

Pharmaceuticals, Inc. (the “Company”) received notice from NYSE American LLC (“NYSE American”) that the Company

was not in compliance with the continued listing standards set forth in Sections 1003(a)(ii) and (iii) of the NYSE American Company Guide

(the “Company Guide”). The Company submitted a compliance plan to NYSE American on June 18, 2026.

On August 12, 2026, the Company received a letter

from NYSE Regulation stating that it had reviewed and accepted the Company’s compliance plan submitted on June 18, 2026 and granted

the Company a plan period through November 27, 2027 (the “Plan Period”) to regain compliance with the applicable continued

listing standards.

During the plan period, while the Company is not

in compliance with the continued listing standards set forth in Sections 1003(a)(ii) and (iii) of the Company Guide, the Company’s

common stock will continue to be listed and traded on NYSE American pursuant to an extension, subject to the Company’s compliance

with the other continued listing requirements of NYSE American and periodic review by NYSE Regulation of the Company’s compliance

with the initiatives outlined in the compliance plan. If the Company does not regain compliance with the applicable continued listing

standards by the end of the Plan Period or does not make progress consistent with the compliance plan during the Plan Period, NYSE Regulation

may initiate delisting proceedings.

Item 7.01. Regulation FD Disclosure.

On August 14, 2026, the Company issued a press

release announcing NYSE Regulation’s acceptance of the Company’s compliance plan. A copy of the press release is furnished

as Exhibit 99.1 to this Current Report on Form 8-K.

The information furnished pursuant to this Item

7.01, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934,

as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated

by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific

reference in such filing.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.

Description

99.1

Press Release dated August 14, 2026

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

Forward-Looking Statements

This Current Report on Form 8-K contains forward-looking

statements within the meaning of the Private Securities Litigation Reform Act of 1995, including statements regarding the continued listing

of the Company’s common stock on NYSE American, the Company’s compliance plan and the Plan Period, and the Company’s

ability to regain compliance with the continued listing standards of the Company Guide. The Company can provide no assurance that it will

make progress that NYSE Regulation determines to be satisfactory, that it will regain compliance during the Plan Period, or that subsequent

developments will not adversely affect its ability to do so or to remain in compliance with other NYSE American continued listing standards.

Forward-looking statements are subject to risks and uncertainties, including those described in the Company’s filings with the Securities

and Exchange Commission, and the Company undertakes no obligation to update any forward-looking statement except as required by law.

SIGNATURES

Pursuant to the requirements of the Securities

Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

ACTINIUM PHARMACEUTICALS, INC.

Date: August 14, 2026

By:

/s/ Sandesh Seth

Name:

Sandesh Seth

Title:

Chairman and Chief Executive Officer

EX-99.1 — PRESS RELEASE DATED AUGUST 14, 2026

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Exhibit 99.1

Actinium Pharmaceuticals Announces Actimab-A

Intellectual Property and Manufacturing Advances and Provides NYSE American Listing Update

NEW YORK, August 14, 2026 /PRNewswire/ –

Actinium Pharmaceuticals, Inc. (NYSE American: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies,

today announced advances across its Actimab-A program, including recently acquired patents adding to a broad suite of IP, and expansion

of the Company’s manufacturing capacity, as the program approaches clinical milestones from the fourth quarter of 2026 and into

2027. The Company also provided an update on the status of its NYSE American listing.

Actiniums holds a broad IP portfolio covering

the manufacture of Actimab-A, as well as its use alone and in combination with other therapies in the treatment of myeloid hematological

malignancies including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), in addition to solid tumor cancers via targeting

of tumor-resident myeloid-derived suppressor cells (MDSCs). Actimab-A patent portfolio activity in the last twelve months:

Actimab-A targeting of myeloid-derived suppressor

cells (MDSCs) for the treatment of solid tumors: Two United States patents issued — US 12,491,274 for the treatment of sarcoma,

expiring 15 October 2043, and US 12,539,340 for the treatment of solid tumors generally, alone or with checkpoint therapy, expiring 31

October 2043. Together they extend the anti-CD33 franchise beyond hematologic malignancy into solid tumors by targeting the immunosuppressive

myeloid cells of the tumor microenvironment rather than the tumor cells themselves. Applications remain pending in the United States,

Canada and Europe.

Actimab-A treatment of low peripheral blast

AML: US 12,410,249 issued, with a term to 12 October 2039, and Canadian application 3,022,802 entered pre-grant status, with a term

to 25 May 2037. Additional patents in this family have already issued in the United States and Japan; applications remain pending in the

United States and Europe.

Actimab-A venetoclax (BCL-2 inhibitor) combination

therapy for the treatment of AML: Canadian application 3,059,752 entered pre-grant status, with a term to 26 April 2038, covering

the use of Actimab-A together with venetoclax in AML. Three patents have already issued in the United States and one in Mexico; applications

remain pending in the United States, Europe, Japan and China.

Actimab-A CLAG-M combination therapy for the

treatment of AML: Canadian application 3,087,346 was allowed, with a term to 8 January 2039. A counterpart patent has already issued

in Japan; applications remain pending in the United States, Europe and Japan.

Actinium has amended its Investigational New Drug

(IND) application to add an additional manufacturer. The additional manufacturer will supply studies conducted under the Company’s

Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute (NCI), together with additional Company-sponsored

studies, which carry clinical milestones expected from the second half of 2026 and throughout 2027. Establishing an additional manufacturing

source is intended to expand capacity and supply flexibility as Actimab-A advances into a broader set of studies across hematologic malignancies

and solid tumors.

NYSE American Listing Update

Actinium also announced today that NYSE Regulation

has accepted the Company’s plan submitted June 18, 2026, to regain compliance with the NYSE American continued listing standards

and granted the Company a plan period through November 27, 2027 (the “Plan Period”) - the maximum period available under Section

1009 of the NYSE American Company Guide (the “Company Guide”).

The Company’s common stock continues to

be listed and traded on NYSE American under the symbol ATNM during the Plan Period, subject to the Company’s compliance with the

terms of the compliance plan and the other continued listing standards of the NYSE American Company Guide. NYSE Regulation staff will

periodically review the Company’s compliance with the initiatives outlined in the compliance plan.

As previously disclosed, the Company is not currently

in compliance with Sections 1003(a)(ii) and 1003(a)(iii) of the NYSE American Company Guide, and its listing is being continued pursuant

to an extension through November 27, 2027.

About Actinium Pharmaceuticals, Inc.

Actinium is a pioneer in targeted radiotherapies

designed to improve outcomes for patients with cancer. The company employs a biology-driven approach to develop differentiated radiopharmaceuticals

for solid tumors and hematologic malignancies. Its mission is to transform cancer treatment through innovative radioconjugates that maximize

therapeutic efficacy while minimizing toxicity to healthy tissue by combining expertise in tumor biology, translational medicine, and

radiochemistry. Since inception, Actinium has focused on developing innovative radiotherapies. Its pipeline reflects this strategy across

three areas: (1) solid tumor therapeutics including ATNM-400 and Actimab-A with pan-tumor potential; (2) Actimab-A as a therapeutic backbone

for acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) in collaboration with the National Cancer Institute (NCI); and (3)

targeted conditioning agents including Iomab-B for bone marrow transplant and Iomab-ACT for cell and gene therapy conditioning. ATNM-400

targets a novel antigen distinct from PSMA and has demonstrated preclinical activity across metastatic castration-resistant prostate cancer

(mCRPC), non-small cell lung cancer (NSCLC), and breast cancer. Actimab-A has shown improved survival in relapsed/refractory AML with

CLAG-M and is advancing toward a Phase 2/3 trial, with additional development ongoing through a CRADA with the NCI. Actinium is also advancing

preclinical solid tumor programs and holds ~250 patents and patent applications, including intellectual property related to cyclotron-based

production of Ac-225. For more information, please visit www.actiniumpharma.com.

Forward-Looking Statements

This press release may contain projections or

other “forward-looking statements” within the meaning of the “safe-harbor” provisions of the Private Securities

Litigation Reform Act of 1995 regarding future events or the future financial performance of the Company which the Company undertakes

no obligation to update. These statements are based on management’s current expectations and are subject to risks and uncertainties

that may cause actual results to differ materially from the anticipated or estimated future results, including the risks and uncertainties

associated with the issuance of allowed patent applications and the scope, term, validity and enforceability of the Company’s intellectual

property, the timing and outcome of the Company’s clinical milestones and data readouts, the performance and qualification of the

Company’s manufacturers and the sufficiency of manufacturing capacity, the Company’s ability to regain compliance with the

NYSE American continued listing standards within the plan period and to maintain the listing of its common stock, preliminary study results

varying from final results, estimates of potential markets for drugs under development, clinical trials, actions by the FDA and other

governmental agencies, regulatory clearances, responses to regulatory matters, the market demand for and acceptance of Actinium’s

products and services, performance of clinical research organizations and other risks detailed from time to time in Actinium’s filings

with the Securities and Exchange Commission (the “SEC”), including without limitation its most recent annual report on Form

10-K, subsequent quarterly reports on Forms 10-Q and Forms 8-K, each as amended and supplemented from time to time.

Investors: investorrelations@actiniumpharma.com

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